Wi-lan Inc.

Microsemi Storage Solutions (u.s.), Inc.

Pmc-sierra, Inc.

Pmc-sierra Us, Inc.

Microsemi Solutions (us), Inc.

Stmicroelectronics Gmbh

Microsemi Storage Solutions, Inc.

Peter Graumann

Sean Gregory Gibb

Stephen Bates

Philip Lyon Northcott

Ron Porat

Yair Bourlas

Kenneth L Stanwood

Srikanth Gummadi

Karle J Johnson

Brian David Petry

Saeed Fouladi Fard

Siavash Sheikh Zeinoddin

Yu Wen

Kripps Asirvatham

Doraid Y Sadiq

Jonathan Eskritt

Kirupairaj Asirvatham

Sina Zahedi

Phil Northcott

Peifang Zhang

A method and system are provided for error correction. After row encoding and column encoding, additional codeword data (ACD) and modified parity (P') may be concurrently created, for each of a plurality of modified column codewords (CCW&#x2032;), by multiplying initial calculated parity P by a generator matrix G. Each CCW&#x2032; may include an ACD portion and a P&#x2032; portion such that each bit in the P&#x2032; portion of a selected CCW&#x2032; is present in the ACD portion for one of the other CCW&#x2032;. In contrast to known approaches, the method and system may provide modified column codewords such that all data and parity bits are present in two codewords while using only two types of codewords, and without using extra parity-on-parity bits. In a set of modified column codewords, each bit in the modified parity in one modified codeword is present in another codeword.

System and method for error correction in data communications

A method and system are provided for drift compensation, providing a live data approach to sampler offset calibration, such as for voltage and/or temperature (VT) drift. A serializer/deserializer (SerDes) system includes a SerDes receiver and receiver logic, the receiver logic including a forward error correction (FEC) module. A drift compensation device, or drift compensation engine, receives live error corrections from the FEC module based on FEC operations performed on live traffic passing through the SerDes receiver. A drift compensation command is provided to a data sampler in the SerDes receiver, to adjust a sampling voltage of the data sampler. When the system includes a plurality of data samplers, the drift compensation device determines the data sampler with which an error correction is associated. The drift compensation command can be sent after a threshold criterion is satisfied, such as completion of a statistics collection period, or a threshold number of corrections.

System and method for drift compensation in data communications

A forward error correction decoder and method of decoding a codeword is provided. The decoder comprises a convergence processor for estimating an expectation of codeword convergence. The convergence processor is configured to calculate a first value of a figure of merit; calculate a second value of the figure of merit; combine the second value of the figure of merit and the first value of the figure of merit to produce a progress value; compare the progress value of the decoding to a progress threshold; and increase a maximum number of iterations of the decoder if the progress value is greater than the progress threshold. The maximum number of iterations may be initially set to a low number beneficial for power consumption and raw throughput. Increasing the maximum number of iterations devotes additional resources to a particular codeword and is beneficial for error rate performance.

Method and system for estimating an expectation of forward error correction decoder convergence

A method and apparatus for a quasi-cyclic low density parity check (QC-LDPC) decoder utilizes a parity check matrix (H matrix) having a matrix value for each row and column position in the matrix. Each matrix value is associated with an initial soft information element where, for each one of the matrix values associated with a constrained row, the one of the matrix values is constrained to a set of constraint values associated with a set of initial soft information elements. The set of initial soft information elements excludes a number of soft information elements that immediately precede a first initial soft information element. The first initial soft information element is associated with a selected first matrix value associated with a first row that immediately precedes the constrained row, and with the same column as the one of the matrix values in the constrained row.

Method and device for forward error correction decoder system utilizing orthogonality of an H matrix

A method for boost floor mitigation during a decoding operation performed by a decoder is disclosed herein. The method includes: monitoring for a floor error condition while performing the decoding operation; if a floor error condition has been detected, then: clearing a feedback delay memory in the decoder; downscaling main memory values in the decoder; applying a gain in low-rank columns; and continuing to perform the decoding operation.

System and method for boost floor mitigation

A method and apparatus as described herein provide a novel modification to any iterative FEC decoder method that can improve FER performance in the error floor region. Many iterative FEC methods, such as commonly used LDPC decoders, have error floors where the performance of the decoder does not improve below a certain threshold. Error Floors are caused by trapping sets from which traditional methods cannot escape. With Stochastic Floor Mitigation, according to embodiments of the present disclosure, noise is strategically added to the operations occurring during decoding resulting in significantly improved error floor performance.

Error correction code decoder with stochastic floor mitigation

An FEC codeword comprises channel information indicating the reliability of the information contained by the FEC codeword. The channel information can be used to generate an initial error channel estimate. Based on the initial error channel estimate, an FEC decoder can decode the FEC codeword to increase the reliability of the information contained by the FEC codeword. According to the present disclosure, a method and system of decoding comprises: comparing a current codeword to a previous codeword in order to identify bits corrected between the previous and current codewords; revising an error channel estimate based on the identified corrected bits, the revised estimate representing a change in the error channel over time; and decoding the codeword based on the revised error channel estimate.

Method and system for forward error correction decoding based on a revised error channel estimate

Forward error correction (FEC) decoders, such as Low Density Parity Check (LDPC) decoders are described. Described FEC decoders minimize the number of internal bits in a layered processor of an LDPC decoder while maintaining high coding gain operation of the LDPC decoder. Minimizing the number of internal bits in a layered processor is achieved by non-linearly companding the soft information into lower precision format while maintaining the dynamic range of the data bits. Described FEC decoders may generate updated soft information having a precision that is equal to the channel precision.

Forward error correction decoder system

A Forward Error Correction (FEC) decoder is provided, for example including a Layered Low Density Parity Check (LDPC) component. In an implementation, power consumption of the LDPC decoder is minimized with minimal to no impact on the error correction performance. This is achieved, in an implementation, by partially or fully eliminating redundant operations in the iterative process.

Forward error correction decoder and method therefor

A method and decoder are provided to decode a Low Density Parity Check codeword. An additional check processor performs hard-decision processing functions on the LDPC codeword in order to avoid running unnecessary decoder iterations. The method comprises: receiving the ECC codeword at a memory, the received ECC codeword comprising ECC data bits, ECC parity bits, and error detection code bits; soft-decision decoding the received ECC codeword at a soft-decision decoder, to update the ECC codeword according to ECC parity check equations; hard-decision processing the received ECC codeword at a check processor, while the soft-decision decoder performs the soft-decision decoding, to verify the ECC data bits using the error detection code bits; terminating the soft-decision decoding when the ECC data bits are verified, regardless of whether the updated ECC codeword satisfies all of the ECC parity check equations; and, outputting the decoded ECC codeword from the memory after termination of the decoding.

High speed LDPC decoder

Apparatus and methods provide relatively low uncorrectable bit error rates, low write amplification, long life, fast and efficient retrieval, and efficient storage density such that a solid-state drive (SSD) can be reliably implemented using various types of memory cells, including relatively inexpensive multi-level cell flash. One embodiment intelligently coordinates remapping of bad blocks with error correction code control, which eliminates the tables used to avoid bad blocks.

Systems and methods for reclaiming memory for solid-state memory

A method of decoding a primary codeword and a set of secondary codewords stored in a non-volatile memory (NVM), which includes reading, from the NVM, the primary codeword and all the secondary codewords and storing them in a second memory. The primary codeword is then read from the second memory and decoded, utilizing a soft-decision decoder, based on a log-likelihood ratio (LLR) vector. When the decoding of the primary codeword is unsuccessful: each secondary codeword of the set of secondary codewords is read from the second memory and decoded, utilizing a hard-decision decoder, to identify and correct errored data bits in the each secondary codeword and to determine a location of each errored data bit in the primary codeword. An adjusted LLR vector is generated by adjusting the LLR for each primary codeword data bit based on the determined locations of the errored data bits in the primary codeword.

Method and system for decoding encoded data stored in a non-volatile memory

A system and method of decoding a Reed-Solomon code using a Reed-Solomon decoder comprising an erasure location selector, multiple syndrome formers and multiple Berlekamp-Massey decoders that share a single error correction unit, and means for selecting a Berlekamp-Massey decoder output as the input to the error correction unit. The method improves the bit error rate performance of the Reed-Solomon decoder compared to known hard-decision and soft-decision Reed-Solomon decoders. The Reed-Solomon decoder also provides hardware area and power savings over more complex Reed-Solomon decoders.

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Calgary, Canada

Peter Graumann